New research finds adult vaccination rates increase when out-of-pocket costs decrease

Adults are more likely to follow government vaccination recommendations when they do not have to pay out of pocket for the vaccine, according to a new study by a University of Massachusetts Amherst researcher. The findings provide important insights into vaccine uptake, as public health officials have experimented with everything from free concert tickets to lotteries with cash prizes to increase COVID-19 vaccination rates.

The full paper, "The Roles of Cost and Recommendations in Driving Vaccine Take-Up," appears in the American Journal of Health Economics.

Though much is known about the strong efficacy of vaccine recommendations for children and adolescents, which are often supported by government funding and requirements for school attendance, this research is among the first to explore how to increase vaccination rates among adults.

Analyzing data from the shingles vaccine, Brandyn Churchill, assistant professor of resource economics at UMass Amherst, and Laura E. Henkhaus, health economist and data scientist with Hill Physicians Medical Group, found that the number of people taking the vaccine nearly doubled after the Affordable Care Act (ACA) required private insurers to cover vaccinations recommended by the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices, as part of preventive care coverage.

"Adults are very price sensitive when it comes to their vaccine decision making," Churchill says. "Cost matters. Age-targeted vaccine recommendations alone don't appear to do a lot for vaccine take-up among adults if the cost is coming out of their wallet."

Churchill and Henkhaus show that prior to the ACA preventive care insurance mandate, adults aged 60 and over, who were recommended to receive the shingles vaccine, were no more likely than their 59-year-old counterparts to be vaccinated. After the ACA mandate took effect in 2010, shingles vaccination increased from 3.1 to 5.9 percentage points for people aged 60 and over.

The research finds a similar increase for people aged 50 to 59 after recommendations for the shingles vaccine were expanded to cover adults aged 50 and over, and private insurance was required to cover it beginning in 2019. This coincided with a more effective and more costly version of the vaccine. Currently, the recommended two doses cost about $200 each.

Churchill notes people with a college education and those who had more contact with the health care system were more likely to take the shingles vaccine after it was fully covered by insurance. "This might say something about an awareness—that they knew they were eligible to get it without patient cost sharing," he says.

Caused by a reactivation of the chickenpox virus, shingles is an infection that can produce a painful rash with fluid-filled blisters. It affects more than one million people in the U.S. each year.

While shingles is not a communicable disease and its mortality rate is very low, the study's findings provide important guidance for policies promoting vaccination against communicable diseases, such as influenza and COVID-19.

"With the COVID vaccines, clearly cost is not the only factor at play, but anything that would increase the cost to adults would likely further reduce vaccine take-up among that group—resulting in potentially serious public health effects," Churchill concludes. COVID vaccines continue to be available with no out-of-pocket cost for most Americans.